Frequencies for first 10,000 rows of sch_bus variable in accident dataset :

 school bus |
    related |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,967       99.67       99.67
          1 |         33        0.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016